Baltimore & Ohio 2-8-8-0 "Consolidation Mallet" Locomotives in the USA


Class Details by Steve Llanso of Sweat House Media

Class EL-1/EL-2/EL-3/EL-5 (Locobase 439)

Alvin F Staufer & Lawrence W Sagle, B & O Power (1964). Data from Record of Recent Construction #91 (Baldwin Locomotive Works, 1918), p.32-33; see also DeGolyer, Vol 55, pp. 389+.

Baldwin works numbers were:

EL-3

1916

January 42832; February 42854-42855; March 43047-43049, 43071-43073; April 43140, 43148-43150, 43275; May 43289

1917

July 45989; August 46112, 46164; September 46267, 46406; October 46677, 46713; December 47282, 47391, 47489

1918

January 47650; February 47746, 47852, 47950; March 48026, 48067, 48130, 48194; April

48277-48279; May 48577, 48682; June 48901, 48902, 48940, 49086-49087; July 49308, 49400; August 49545

EL-5

1919

September 52371, 52425; November 52464-52468, 52518-52520, 52552-2555, 52598-52605; December 52642-52645

Baldwin reported that these huge locomotives were intended for the 2.4% grades in the Cumberland Division, over which they would haul long, loaded trains of coal cars. Substantially bigger than the Alcos shown as LL-1s 0-8-8-0s in Locobase 9617 and 2-8-8-0s in Locobase 16285, these engines disposed 41% more superheater area and increased combustion chamber length by 22" (559 mm).

The cylinders used a combination of 14" (356 mm) piston valves for the HP cylinders actuated by Baker gear and Allen balanced slide valves for the LP cylinders operated by Walschaert's gear. (Thanks to Chris Hohl for providing an example of the weird-looking result.) When the LP cylinders were rebuilt with piston valves, they were opened by Baker gear.

Four arch tubes contributed 35 sq ft (3.25 sq m) to the firebox heating surface area.

Definitely intended for main-line service, these big articulateds were able to negotiate curves as sharp as 22 deg. Total weight distribution varied by only 1,100 lb between the front and rear engine units.

Several classes beginning with 15 EL-1 (1916) and followed by 15 EL-2 (7200-7214 in 1916), 30 EL-3 (7115-7144 in 1917) and 26 EL-5 (7145-7170 in 1919-1920) -- all by Baldwin.

All surviving locomotives were converted to four-cylinder simple-expansion engines from 1927 on after the prototype demonstrated a considerable improvement in pulling power; see Locobase 305.

The last of these left service in 1954.


Class EL-3a/EL-5a (Locobase 305)

Data from tables in 1930 Locomotive Cyclopedia.

These were B&O rebuilds of B&O compound Mallets (Locobase 439) to four-cylinder simple-expansion machines beginning in 1927. 64 engines were converted altogether, all to the same powerful standard.

Compared to the EL-6a conversion (Locobase 3556), these locomotives didn't work quite so hard, but steamed as easily. All four cylinders used 14" (356 mm) piston valves.

Smaller drivers undoubtedly confined them to hill work, where they served until the early 1950s.


Class EL-4 (Locobase 16285)

Data from B & O to 1954 Asstd Loco Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange.

Locobase 9617 shows the original LL-1 0-8-8-0 class as delivered in 1911-1912.

According to Drury (1993), these big engines proved "slow and complicated". Several were rebuilt as EL-4 class 2-8-8-0s simply by adding a leading truck. A B&O Locomotive Roster dated 1 January 1934 shows only eight converted to that arrangement; the other 22 were still classed as LL-1. The 1946 roster shows that one more LL-1 (7039) was converted during the war years. The 7041 and 7049, originally delivered in 1913, had engine weighst of 482,500 lb (218,859 kg) each.

Still, all nine served throughout World War Two before being scrapped in 1949-1950.


Class EL-6a (Locobase 3556)

Data from Wiener (1930) supplemented by B&O to 1954 Assorted Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. (Thanks to Chris Hohl for correcting the valve gear ID.)

These were simpled conversions of SAL 2-8-8-2s (Locobase 15148) that had come onto the B&O in 1922. They had a relatively high driver diameter and a hard-worked, but relatively free-steaming boiler. The last of these left service in 1954.

Principal Dimensions by Steve Llanso of Sweat House Media
ClassEL-1/EL-2/EL-3/EL-5EL-3a/EL-5aEL-4EL-6a
Locobase ID439 305 16,285 3556
RailroadBaltimore & Ohio (B&O)Baltimore & Ohio (B&O)Baltimore & Ohio (B&O)Baltimore & Ohio (B&O)
CountryUSAUSAUSAUSA
Whyte2-8-8-02-8-8-02-8-8-02-8-8-0
Number in Class8664916
Road Numbers7100-71707100-71707020, 7023, 7032-7033, 7036, 7038-7040, 70497300-7315
GaugeStdStdStdStd
Number Built86
BuilderBaldwinB & OAlco-SchenectadyB & O
Year1916192719191922
Valve GearBaker or WalschaertBaker or WalschaertBakerSouthern
Locomotive Length and Weight
Driver Wheelbase (ft / m)15.50 / 4.7215.50 / 4.7215 / 4.5715.46 / 4.71
Engine Wheelbase (ft / m)50.33 / 15.3450.33 / 15.3449.71 / 15.1553.33 / 16.25
Ratio of driving wheelbase to overall engine wheebase 0.31 0.31 0.30 0.29
Overall Wheelbase (engine & tender) (ft / m)82.61 / 25.1882.61 / 25.1886.29 / 26.3098.27 / 29.95
Axle Loading (Maximum Weight per Axle) (lbs / kg)58,00063,400 / 28,75861,300
Weight on Drivers (lbs / kg)462,500 / 209,787459,400 / 208,381455,300 / 206,521456,700 / 207,156
Engine Weight (lbs / kg)485,600 / 220,265484,400 / 219,720471,300 / 213,778492,000 / 223,168
Tender Loaded Weight (lbs / kg)206,400 / 93,622262,000181,500 / 88,904219,000 / 99,337
Total Engine and Tender Weight (lbs / kg)692,000 / 313,887746,400652,800 / 302,682711,000 / 322,505
Tender Water Capacity (gals / ML)12,000 / 45.4518,000 / 45.459500 / 45.4512,000 / 45.45
Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)20 / 18.2018 / 16.4016 / 11.4020 / 18.20
Minimum weight of rail (calculated) (lb/yd / kg/m)96 / 4896 / 4895 / 47.5095 / 47.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)58 / 147358 / 147356 / 142263 / 1600
Boiler Pressure (psi / kPa)210 / 14.50210 / 14.50225 / 15.50225 / 15.50
High Pressure Cylinders (dia x stroke) (in / mm)26" x 31" / 660x78724" x 32" / 610x813 (4)26" x 32" / 660x81325" x 32" / 635x813 (4)
Low Pressure Cylinders (dia x stroke) (in / mm)41" x 31" / 1041x78741" x 32" / 1041x813
Tractive Effort (lbs / kg)91,993 / 41727.37113,452 / 51461.02105,378 / 47798.71121,429 / 55079.33
Factor of Adhesion (Weight on Drivers/Tractive Effort) 5.03 4.05 4.32 3.76
Heating Ability
Firebox Area (sq ft / m2)393 / 36.52341 / 31.69321.50 / 29.87398 / 36.99
Grate Area (sq ft / m2)88.17 / 8.1988.17 / 8.19100 / 9.2988 / 8.18
Evaporative Heating Surface (sq ft / m2)5836 / 542.385784 / 537.555641 / 524.065922 / 550.37
Superheating Surface (sq ft / m2)1415 / 131.511415 / 131.511002 / 93.091380 / 128.25
Combined Heating Surface (sq ft / m2)7251 / 673.897199 / 669.066643 / 617.157302 / 678.62
Evaporative Heating Surface/Cylinder Volume306.36172.60286.87162.87
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation18,51618,51622,50019,800
Same as above plus superheater percentage22,21922,21925,87523,562
Same as above but substitute firebox area for grate area99,03685,93283,188106,565
Power L1880012,251698613,210
Power MT335.58470.33270.62510.15

  • 7100 (Eckington Yards, Washington, D.C., June 4, 1923)
  • 7109
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